如何以编程方式设置按钮位置？

Question

In my code I create button two programmatically how do I set is position to center of screen programmatically? This is my image of screen https://imgur.com/7wdyVc6 submit button(button2) is create just below forloop button how do I set is position to center of screen?

    ScrollView scroll = new ScrollView(MainActivity1.this);
    scroll.setLayoutParams(new  
      LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,  
        LayoutParams.WRAP_CONTENT));         

    btnLO = new LinearLayout(MainActivity1.this);   
    LinearLayout.LayoutParams paramsLO = new  
      LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    // button margins
    paramsLO.setMargins(0, 0, 0, 0);
    // button height/width *pixels*
    paramsLO.height = 75;
    paramsLO.width = 75;

    btnLO.setOrientation(LinearLayout.VERTICAL);
    btnLO.setBackgroundColor(5); // not working correctly

    //buttons
    for (i = 0;i < reqdata.length;i++)
    {
        LinearLayout li=new LinearLayout(this);
        li.setOrientation(LinearLayout.HORIZONTAL);
        final Button b1 = new Button(MainActivity1.this);
        final ImageView imageView = new ImageView(MainActivity1.this);

        li.addView(b1, paramsLO);        
        li.addView(imageView, paramsLO);
        btnLO.addView(li);

        b1.setText(reqdata[i].getSpinnerText());

        b1.setOnClickListener(new View.OnClickListener()
        {
            public void onClick(View v) 
            {
                imageView1 = imageView;
                Intent pictureActionIntent = new
                  Intent(MediaStore.ACTION_IMAGE_CAPTURE); 

                pictureActionIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new  
                File(SDCARD_ROOT_PATH + SAVE_PATH_IN_SDCARD,IMAGE_CAPTURE_NAME)));  

                startActivityForResult(pictureActionIntent,CAMERA_PICTURE);
                b1.setClickable(false);
            }   
        });
    }

    final Button b2 = new Button(MainActivity1.this);
    b2.setText("Submit");
    b2.setOnClickListener(new View.OnClickListener() 
    {
        public void onClick(View v) 
        {
            long visitID = dbConnector.saveVisit();

            for (i =0;i <reqdata.length;i++)
            {
                dbConnector.saveVisitDetail(listByte.get(i),visitID,Long.valueOf(reqdata[i]
                  .getValue()).longValue());
            }
        }
    }); 
    btnLO.addView(b2, paramsLO);
    btnLO.setGravity(Gravity.LEFT | Gravity.CENTER_HORIZONTAL);
    scroll.addView(btnLO);

    this.addContentView(scroll, new LayoutParams());
}

Answer 1

One possible way is to use the RelativeLayout as your base layout and add all other children views to this layout using the RelativeLayout.LayoutParams class for setting the layout parameters.

The RelativeLayout.Layoutparams.left and RelativeLayout.Layoutparams.top attributes can be your (x,y) co- ordinates on the base view.

Answer 2

in your activity xml, copy paste the following in the desired button component:

android:layout_marginBottom="147dp"
android:layout_marginTop="50dp"
android:layout_marginleft="50dp"
android:layout_marginRight="47dp"

play only with the numbers and I'm sure u'll get the hang of it :)